1. Field of the Invention
This invention relates to an anti-corrosive sealing tape which can protect structural members such as underground water pipes, gas pipes or chemical plant pipes against corrosion when wrapped around them.
2. Description of the Prior Art
Coating or resin lining has been previously used to protect structural members such as metal pipes against corrosion. However, these methods do not have corrosion preventive functions and exhibit a short life duration because of the presence of water infiltrating through a void formed by spontaneous expansion of film, an interface between a resin and a reinforcing agent or vehicle, a foam or the like.
Alternatively, anti-corrosive sealing tapes have also been used. A well-known example of an anti-corrosive sealing tape, which is prepared by extruding an adhesive composition containing a rubber base, graphite powder, silica, zinc oxide powder, a non-reactive phenolic condensate and other additives such as oil on a tape, has been disclosed in British Pat. No. 1,532,294. The function of this adhesive is to insulate a member wrapped therewith against its environment with a higher adhesiveness than that of a conventional coating or resin lining. That is to say, the aforementioned adhesive does not contain any ingredient which exhibits an active anoding effect by itself, such as zinc.